1. Technical Field
The present invention relates to a semiconductor device, and more particularly, to a micro-processor.
2. Related Art
A conventional micro-processor is operated to repetitively perform basic processes consisting of four steps such as fetch, decoding, execution, and write-back. For this, the micro-processor includes a clock generator and performs the steps, such as the fetch, decoding, execution, and write-back, for each rising edge of a system clock that is generated from the clock generator. That is, the processes are performed using four periods of the system clock as one unit.
The micro-processor moves program data input in a program input device to at an initial operation a memory device and stores the program data in the memory device. Thereafter, when the system clock is activated, the micro-processor activates transmits the program data stored in the memory device to a command decoder in the fetch step. In the decoding step, the micro-processor activates the command decoder, and decodes data transmitted from the memory device. In the execution step, the micro-processor activates an arithmetic device, and performs an arithmetic operation on signals transmitted from the command decoder according to each command. In the write-back step, the micro-processor activates a register and a peripheral circuit device, and stores arithmetic results by the arithmetic device or performs a communication operation with the outside, a counting operation, etc., according to each command transmitted from the command decoder.
In the technical development of the micro-processor, low power implementation has been recently highlighted as the most important issue. This is because a demand of a low power micro-processor is increased due to devices, such as mobile communication devices, etc., that are sensitive to power consumption. Therefore, a study to reduce power consumption such as leakage current in each circuit area of the micro-processor has been actively progressed.
However, the micro-processor according to the related art is configured so that all the circuit areas are operated by the system clock. Therefore, the circuit areas, which do not perform the real operations, are activated, thereby consuming current. In addition, since the micro-processor is operated so that the program data is stored in a non-volatile memory device that consumes a large amount of current and has a limited operational speed and reads the stored program data from the non-volatile memory device, it is difficult to technically implement a low-power and high-speed micro-processor.